1.1.5 Ensure separate partition exists for /var (Scored)
Profile Applicability
Level 2 - Server Level 2 - Workstation
Description
The /var directory is used by daemons and other system services to temporarily store dynamic data. Some directories created by these processes may be world-writable.
Rationale
Since the /var directory may contain world-writable files and directories, there is a risk of resource exhaustion if it is not bound to a separate partition.
Audit
Run the following command and verify output shows /var is mounted:
# mount | grep /var /dev/xvdg1 on /var type ext4 (rw,relatime,data=ordered)
Remediation
For new installations, during installation create a custom partition setup and specify a separate partition for /var.
For systems that were previously installed, create a new partition and configure /etc/fstab as appropriate.
Impact
Resizing filesystems is a common activity in cloud-hosted servers. Separate filesystem partitions may prevent successful resizing, or may require the installation of additional tools solely for the purpose of resizing operations. The use of these additional tools may introduce their own security considerations.
References
AJ Lewis, “LVM HOWTO”, http://tldp.org/HOWTO/LVM-HOWTO/